Aqueous interfaces, nanobubbles and the effect of ions on these interfaces, have been extensively investigated due to the importance of their behaviour in many fields. This book, further refined at Key Laboratory of Solid Waste Treatment and Resource Recycle Ministry of Education, in Southwest University of Science and Technology, has expanded our understanding of the air-aqueous interfacial structure and the molecular mechanism of ion effect on nano-film stability, for the support of aqueous film or nanobubble applications.